diff --git a/drivers/pci/setup-res.c b/drivers/pci/setup-res.c
index 232f9254c11acf5b45d9b20f9fc4169dfad79084..54c4f4f8105d4fc21bd357d6136d63dc169fc7ba 100644
--- a/drivers/pci/setup-res.c
+++ b/drivers/pci/setup-res.c
@@ -177,6 +177,7 @@ static int pci_revert_fw_address(struct resource *res, struct pci_dev *dev,
 	end = res->end;
 	res->start = fw_addr;
 	res->end = res->start + size - 1;
+	res->flags &= ~IORESOURCE_UNSET;
 
 	root = pci_find_parent_resource(dev, res);
 	if (!root) {
@@ -194,6 +195,7 @@ static int pci_revert_fw_address(struct resource *res, struct pci_dev *dev,
 			 resno, res, conflict->name, conflict);
 		res->start = start;
 		res->end = end;
+		res->flags |= IORESOURCE_UNSET;
 		return -EBUSY;
 	}
 	return 0;